Insecticidal triffluormethyl alkane derivatives

ABSTRACT

There are provided new alkane and alkoxyalkane derivatives of the general formula Iin which R1, R2, R3, R4 and A have the meanings given in the description, processes for their preparation and insecticidal and acaricidal compositions containing these compounds.

The invention relates to new alkane and alkoxyalkane derivatives,processes for their preparation and insecticidal and acaricidalcompositions containing these compounds.

It is already known that certain alkane and alkoxyalkane derivativespossess insecticidal and acaricidal properties (DE-OS No. 31 17 510 andDE-OS No. 33 17 908).

The object of the present invention is the preparation of new compoundsthat combat insects and spider mites better than compounds known forthis purpose.

The alkane and alkoxyalkane derivatives of the invention are of thegeneral formula I

in which

R₁ is aromatic or aromatic substituted by C₁₋₄ alkyl, halo-C₁₋₄ alkyl,phenyl-C₁₋₄ alkyl, C₂₋₄ alkenyl, halo-C₂₋₄ alkenyl, phenyl-C₂₋₄ alkenyl,C₂₋₄ alkynyl, halo-C₂₋₄ alkynyl, phenyl-C₂₋₄ alkynyl, C₁₋₄ alkoxy,halo-C₁₋₄ alkoxy, phenyl-C₁₋₄ alkoxy, C₂₋₄ alkenyloxy, halo-C₂₋₄alkenyloxy, phenyl-C₂₋₄ alkenyloxy, C₂₋₄ alkynyloxy, halo-C₂₋₄alkynyloxy, phenyl-C₂₋₄ alkynyloxy, alkylsulphonyloxy,haloalkylsulphonyloxy, arylsulphonyloxy, halo, cyano, nitro, aryloxy,haloaryloxy, C₁₋₄alkyl-aryloxy, or nitroaryloxy,

R₂ is hydrogen or C₁₋₄ alkyl,

R₃ is hydrogen, cyano or ethynyl,

R₄ is phenyl or pyridyl or these groups substituted by one or more ofC₁₋₆ alkyl, halo-C₁₋₆ alkyl, phenyl-C₁₋₆ alkyl, C₂₋₆ alkyl interruptedby an O-, N- or S-atom, C₂₋₄ alkenyl, halo-C₂₋₄ alkenyl, phenyl-C₂₋₄alkenyl, C₁₋₄ alkoxy, halo-C₁₋₄ alkoxy, phenyl-C₁₋₄ alkoxy, C₂₋₄alkenyloxy, halo-C₂₋₄ alkenyloxy, phenyl-C₂₋₄ alkenyloxy, C₂₋₄alkynyloxy, halo-C₂₋₄ alkynyloxy, phenyl-C₂₋₄ alkynyloxy, aryloxy,haloaryloxy, C₁₋₄ alkylaryloxy, arylamino, haloarylamino, C₁₋₄alkylarylamino, aryl-N-C₁₋₄ alkylamino, aryl-N-C₁₋₄ acylamino, aroyl,haloaroyl, C₁₋₄ alkylaroyl, aryl, haloaryl, C₁₋₄ alkylaryl or halo, and

A is C₂ or O.

It has been found that these compounds have a better insecticidal andacaricidal activity than structurally similar compounds.

The compounds of the invention are surprisingly highly active against anumber of important plant pests, such as for example Plutellaxylostella, Epilachna verivestis and Spodoptera littoralis. For thisactivity, highly active insecticides are known that can be used forcombating these plant pests. The compounds of the invention also haveactivity against a number of economically important animal ectoparasitesand public health pests.

The aromatic group designated as R₁ in general formula I includes aryland heteroaryl such as phenyl, 1-naphthyl, 2-naphthyl, benzofuran-5-yl,benzothiophen-5-yl, benzofuran-6-yl, benzothiophen-6-yl,benzoxazol-5-yl, benzoxazol-6-yl, indan-5-yl, indan-6-yl,1,4-benzodioxan-6-yl, 1,3-benzodioxan-6-yl, 1,3-benzodioxan-7-yl,1,3-benzodioxol-5-yl and 5,6,7,8-tetrahydronaphthyl.

Compounds of the invention showing particularly good insecticidal andacaricidal activity are those in which in general formula I

R₁ is chlorophenyl, bromophenyl, fluorophenyl, methylphenyl,methoxyphenyl, ethoxyphenyl, difluoromethoxyphenyl, fluorethoxyphenyl,or trifluoroethoxyphenyl,

R₂ is hydrogen or methyl,

R₃ is hydrogen,

R₄ is phenoxyphenyl, fluorophenoxyphenyl or phenoxypyridyl and

A is CH₂ or O.

The compounds of the invention exist as optional isomers. The inventionincludes all isomers as well as mixtures of them.

The compounds of the invention, where A=CH₂, can be prepared for example

(a) reacting a compound of general formula II

or of general formula III

first with a base and then with a compound of general formula IV

to give a compound of general formula V

and then reducing this to the desired product, or

(b) reacting a compound of general formula VI

first with a base and then with a compound of general formula VII

to give a compound of general formula VIII

and then reducing this to the desired product, or

(c) condensing a compound of general formula IX

with an aldehyde of general formula X

R₄CHO   (X)

to given an α,β-unsaturated compound of general formula XI

and then reducing this to the desired product or

(d) condensing a compound of general formula XII

with an aldehyde of general formula IV

to give an α,β-unsaturated compound of general formula XIII

and then reducing this to the desired product, in which R₁, R₂, R₃ andR₄ have the meanings given above and R₅ is alkyl or phenyl, R₆ is isalkyl and X is halogen.

The compounds of the invention, where A=O, can be prepared for example

(a) reacting a compound of general formula XIV

with a compound of general formula XV

in the presence of a base and using a solvent, or

(b) reacting a compound of general formula XVI

with a compound of general formula XVII

in the presence of a base and using a solvent, in which R₁, R₂, R₃ andR₄ have the meanings given above and Z is halogen, methanesulphonate ortoluenesulphonate.

The reaction with the phosphonium salts or the phosphonates of generalformula II, III and VI can be carried out, for example in the presenceof an inert solvent, such as that generally used in Wittig reactions.Suitable solvents include alaphatic or aromatic hydrocarbons, such asfor example hexane, benzene or toluene, and ethers such as for examplediethyl ether and tetrahydrofuran. Other suitable solvents are amides,such as dimethylformamide or hexamethylphosphoric acid triamide. In somecases, alcohols or dimethyl sulphoxide can be used.

Suitable bases for the Wittig reaction include metal alcoholates, suchas for example sodium ethanolate, metal hydrides, such as for examplesodium hydride, metal amides, such as for example sodium amide andorganometalic compounds, such as for example phenyllithium orbutyllithium.

The compounds of general formula I in which the group R₁ is analkoxyphenyl or haloalkoxyphenyl group etc., and A=CH₂, can also beobtained by treatment of a hydroxyphenyl derivative that can be preparedby hydrolysis of another alkoxyphenyl derivative, for example with thecorresponding alkyl halide.

The etherification is generally carried out in solution. Suitable basesinclude metal alcoholates, such as for example potassium tert.-butylate,metal hydrides, such as for example sodium hydride, metal amides, suchas for example lithium diisopropylamide and metal alkyl compounds, suchas for example ethyl mangnesium bromide or butyllithium.

Suitable solvents, as opposed to the reactants, especially the bases,include inert substances such as aliphatic and aromatic hydrocarbonssuch as for example hexane, benzene or toluene and ethers such as forexample diethyl ether, tetrahydrofuran or dimethoxyethane. Suitablefurther amides include dimethylformamide, N-methylpyrrolidone orhexamethylphosphoric acid triamide.

The etherification can further be carried out in a two phase system byusing a catalyst and optionally a solvent. Bases that can be usedinclude alkali metal hydroxides or alkali metal carbonates, either assolids or an aqueous solution. Suitable solvents are the reactantsthemselves as long as they are liquid. Otherwise they can be used insubstances which are inert to the bases and which are immiscible withwater, such as aliphatic or aromatic hydrocarbons, such as for examplehexane, benzene of toluene. Suitable catalysts include crown ethers andquaternary ammonium salts, such are described in Dehmlow and Dehmlow,Phase Transfer Catalysts, Weinheim 1980.

The reaction can be carried out at temperatures between −78° and 140°C., preferably at 20°-80° C., generally at room temperature.

The carbonyl compounds starting materials of general formula IV in whichR₂=H, and those of general formula VII are known either as such or astheir analogues (R₁=phenyl) and can be prepared according to methodsdescribed in the literature (F. E. Herkes, D. J. Burton, J. Org. Chem.32, 1316 (1967); R. Stewart, K. C. Teo, Can. J. Chem. 58, 2491 (1980);C. Aaron, D. Dull, J. L. Schmiegel, D. Jaeger, Y. Ohashi, H. S. MosherJ. Org. Chem. 32, 2797 (1967).

The aldehyde compounds of formula IV, used as starting materials, inwhich R₂ is H, can be prepared by reacting a compound of general formulaXVIII

which can be themselves prepared by methods described in literature,with a cyanisation reagent, such as for example trimethylsilyl cyanide,in the presence of a Lewis acid, such as for example TiCl₄ or SnCl₄,optionally using a solvent (M. T. Reetz, I. Chatziiosifidis, Angew.Chem. 93. 1075 (1981); R. Davis, K. G. Untch, J. Drg. Chem. 46, 2987(1981) and then reducing the resulting nitrile of general formula XIX

to the desired aldehyde in conventional manner. R₁ and R₂ have themeanings given above and Y is a hydroxy group or a leaving group, suchas for example halogen.

The compounds of general formula XIX, in which the group R₁ is analkoxyphenyl or haloalkoxyphenyl group etc. can be obtained also bytreatment of the corresponding hydroxyphenyl derivatives, (whichthemselves can be prepared by hydrolysis of another alkoxyphenylderivative), for example by using the corresponding alkyl halide.

The phosphonium salt or phosphonate starting material of general formulaII, III and VI can be obtained by treatment of R₄CH(R₃)CH₂X orR₄CH(R₃)CH₂CH₂X, wherein X is a halogen atom, with (R₅)₃P or (R₆O)₃P.

The alcohols used as starting materials of general formula XIV and XVIIcan be prepared by reduction of the corresponding nitrile, aldehyde,carboxylic acid or carboxylic acid ester. The reaction can be carriedout according to known methods with metal hydride complexes, for examplelithium aluminium hydride or alkyl aluminium hydrides for examplediisobutylaluminium hydride. The halonide, tosylate and mesylates whichare used, are known in themselves or can be prepared according to knownmethods (DE-OS No. 31 17 510, DE-OS No. 33 17 908, Houben-Wevl, Band5/4, page 354; ibid. Band 9, page 663).

The compounds of the invention prepared by the above described processescan be isolated from the reaction mixture in conventional manner, forexample by distillation of the solvent used at normal or reducedpressure or by extraction.

A higher degree of purity can be obtained as general rule by thin layerchromatography purification or by fractional distillation.

The compounds of the invention are, as a rule, colourless oils that arehighly soluble in practically all organic solvents but are almostinsoluble in water.

The compounds according to the invention can be used at a concentrationof 0.005 to 5%, preferably from 0.001 to 1%, calculated as gram activematerial per 100 ml of the composition.

The compounds of the invention can be used either alone or in mixturewith each other or another insecticide. Optionally other plantprotection or pesticidal compositions, such as for example insecticides,acaricides or fungicides can be added depending on the desired result.

An improvement in the intensity and speed of action can be obtained, forexample, by addition of suitable adjuvants, such as organic solvents,wetting agents and oils. Such additives may allow a decrease in thedose.

Suitable mixture partners may also include phospholipids, e.g. such asfrom the group phosphatidylcholine, hydrated phosphatidylcholine,phosphatidylethanolamine, N-acyl-phosphatidylethanolamine,phosphatidylinositol, phosphatidylserine, lysolecithin orphosphatidylglycerol.

The designated active ingredients or their mixtures can suitably beused, for example, as powders, dusts, granules, solutions, emulsions orsuspensions, with the addition of liquid and/or solid carriers and/ordiluents and, optionally, binding, wetting, emulsifying and/ordispersing adjuvants.

Suitable liquid carriers are, for example aliphatic and aromatichydrocarbons such as benzene, toluene, xylene, cyclohexanone,isophorone, dimethyl sulphoxide, dimethylformamide, other mineral-oilfractions and plant oils.

Suitable solid carriers include mineral earths, e.g. tonsil, silica gel,talcum, kaolin, attapulgite, limestone, silicic acid and plant products,e.g. flours.

As surface-active agents there can be used for example calciumlignosulphonate, polyoxyethylenealkylphenyl ether, naphthalenesulphonicacids and their salts, phenolsulphonic acids and their salts,formaldehyde condensates, fatty alcohol sulphates, as well assubstituted benzenesulphonic acids and their salts.

The percentage of the active ingredient(s) in the various preparationscan vary within wide limits. For example, the compositions can containabout 10 to 90 percent by weight active ingredients, and about 90 to 10percent by weight liquid or solid carriers, as well as, optionally up to20 percent by weight of surfactant.

The agents can be applied in customary fashion, for example with wateras the carrier in spray mixture volumes of approximately 100 to 3,000l/ha. The agents can be applies using low-volume or ultra-low-volumetechniques or in the form of so-called microgranules.

The preparation of these formulations can be carried out in a knownmanner, for example by milling or mixing processes. Optionally,individual components can be mixed just before use for example by theso-called commonly used tank-mixing method.

Formulations can be prepared, for example, from the followingingredients.

(a)

80 percent by weight active ingredient

15 percent by weight kaolin

5 percent by weight surface-active agent based on the sodium salt ofN-methyl-N-oleyltaurine and the calcium lignosulphonate

(b)

45 percent by weight active ingredient

5 percent by weight sodium aluminium silicate

15 percent by weight cetylpolyglycol ether with 8 moles ethylene oxide

2 percent by weight spindle oil

10 percent by weight polyethylene glycol

23 parts water

(c)

20 percent by weight active ingredient

35 percent by weight bentonite

8 percent by weight calcium lignosulphonate

2 percent by weight of the sodium salt of N-methyl-N-oleyltaurine

35 percent by weight silicic acid

(d)

20 percent by weight active ingredient

75 percent by weight isophorone

5 percent by weight of an emulsifier mixture of calcium phenylsulphonateand fatty alcohol polyglycol ether

The following examples illustrate the preparation of compounds accordingto the invention.

EXAMPLE 15-(4-Fluoro-3-phenoxyphenyl)-2-(4-methoxyphenyl)-2-trifluoromethylpentane

1-(4-Fluoro-3-phenoxyphenyl)-4-(4-methoxyphenyl)-4-trifluoromethyl-2-pentene(15.12 g; 37.76 mmol) was hydrogenated in methanol (200 ml) withhydrogen using Raney nickel (5 g) at room temperature and underatmospheric pressure. After the calculated amount of hydrogen had beentaken up, the catalyst was filtered off and the solvent removed underreduced pressure. After chromatography on silica gel using ethylacetate/hexane as eluant, there was obtained a 10.1 g of product (=61.8%of theory).

n_(D) ²⁰:1.5434.

Preparation of the Starting Material

A solution of butyllithium in hexane (1.6 molar; 30 ml) was added,dropwise, under a nitrogen atmosphere to[2-(4-fluoro-3-phenoxyphenyl)ethyl]triphenylphosphonium bromide (26.76g; 48 mmol) in absolute tetrahydrofuran (200 ml). After stirring for twohours, 2-(4-methoxyphenyl)-2-trifluoromethylpropionaldehyde (10.13 g;43.63 mmol) dissolve in absolute tetrahydrofuran (80 ml) was added,dropwise. The mixture was heated at reflux for 3 hours and then added toice-water, extracted with ethyl acetate, the extract dried over sodiumsulphate and evaporated. After chromatography on silica gel usinghexane/ethyl acetate as eluent, there was obtained1-(4-fluoro-3-phenoxyphenyl)-4-(4-phenoxyphenyl)-4-trifluoromethyl-2-pentene(15.2 g=80.5% of theory).

A 1.2 molar solution of diisobutylaluminium hydride in toluene (46 ml)was added, dropwise, to2-(4-methoxyphenyl)-2-trifluoromethylpropionitrile (10.0 g; 43.6 mmol)in absolute toluene (100 ml) at a temperature of 5° to 10° C. Afterstirring at room temperature for 3 hours, the mixture was added toice-water, acidified with dilute hydrochloric acid, extracted with ethylacetate, the organic phase was washed with water and dried over sodiumsulphate. There was obtained2-(4-methoxyphenyl)-2-trifluoromethylpropionaldehyde (9.5 g=93.7% oftheory).

Trimethylsilyl cyanide (65.1 ml; 423 mmol) was added at room temperatureto 1-chloro-1-(4-methoxyphenyl)-1-trifluoromethylethane (77.6 g; 335.5mmol) in methylene chloride (975 ml) followed by titanium tetrachloride(32.5 ml; 3.25 mmol). After stirring for 20 hours at room temparature,2N sodium hydroxide was added carefully, dropwise, until the mixture wasneutral and the precipitate separated over celite. The aqueous phase wasextracted with ethyl acetate and the extract dried over sodium suphate.After concentrating, there was obtained2-(4-methoxyphenyl)-2-trifluoromethylpropionitrile (71.49 g=90% oftheory).

Titanium tetrachloride (42.3 ml; 42.17 mmol) was added, dropwise, atroom temperature to 1-(4-methoxyphenyl)-1-trifluoromethylethanol inmethylene chloride (100 ml). After stirring for 1 hour, the mixture wasadded to ice-water, extracted with methylene chloride, washed first withsaturated sodium hydrogen carbonate solution and then with water, driedover sodium sulphate and concentrated. Following distillation in arotary evaporator at 150° C./0.5 ml, there was obtained1-chloro-1-(4-methoxyphenyl)-2-trifluoromethylethane (77.67 g=76.7% oftheory).

1,1,1-Trifluoroacetone (60.4 ml; 675 mmol) dissolved in absolute ether(80 ml) was added, dropwise, at 5° to 10° C. to an ethereal Grignardsolution (prepared from p-bromoanisole (84.17 g; 450 mmol) and magnesium(10.9 g; 450 mmol) in ether (600 ml)) and the mixture stirred at roomtemperature for 20 hours. It was then added to saturated ammoniumchloride solution, extracted with ether and the extract washed withwater, dried over sodium sulphate and concentrated. The precipitate wasfiltered off washed with hexane and the filtrate concentrated.1-(4-methoxyphenyl)-1-trifluoromethylethanol (93.35 g=94.2% of theory)was obtained as a brown oil that was used without further purification.(The alcohol can also be coverted direct to the nitrile in a one-potreaction.

EXAMPLE 2[2-(4-Ethoxyphenyl)-2-trifluoromethylpropyl](4-fluoro-3-phenoxybenzyl)ether

Sodium hydride (144 mg; 6 mmol) was suspended in dimethoxyethane (16 ml)and then in turn, with stirring, there was added2-(4-ethoxyphenyl)-2-trifluoromethyl-1-propanol (1.25 g; 5.044 mmol), aspatula of sodium iodide and 4-fluoro-3-phenoxybenzyl bromide (1.4 g;5.04 mmol). After stirring for 5 hours at room temperature, the mixturewas added to ice-water, extracted 3 times with ether and the extractswashed with water dried over sodium sulphate and evaporated. Afterchromatography on silica gel using a mixture of ethyl acetate andhexane, there was obtained 2.06 g of product (=91.1% of theory).

n₂₀D; 1.5375.

Preparation of the Starting Material

2-(4-Ethoxyphenyl)-2-trifluoromethylpropionaldehyde (4.23 g; 17.18mmol), prepared as described in Example 1 for2-(4-methoxyphenyl)-2-trifluoromethylpropionaldehyde, was reduced withsodium borohydride in isopropanol (Organikum, VEB Deutscher Verlag derWissenschaften, Berlin 1976, page 616). After working up andchromatography on silica gel using hexane/ethyl acetate, there wasobtaine 2.71 g of 2-(4-ethoxyphenyl)-2-trifluoromethyl-1-propanol(=63.7% of theory).

EXAMPLE 3 4-(3-Phenoxyphenyl)-1-phenyl-1-trifluoromethylbutane

4-(3-Phenoxyphenyl)-1-phenyl-1-trifluoromethyl-1-butene (3.18 g; 8.6mmol) was hydrogenated in ethanol (40 ml) with hydrogen with theaddition of Raney nickel (0.4 g) at room temperature and underatmospheric pressures. After the calculated amount of hydrogen had beentaken up, the catalyst was filtered off and the solvent removed underreduced pressure. After chromatography on silica gel withhexane/toluene, there remained 2.49 g of product (=78% of theory).

n₂₀D: 1.5463.

Preparation of the Starting Material

A solution of butyllithium in n-hexane (8.5 ml of 1.6 molar) was added,dropwise, at room temperature and under a nitrogen atmosphere over 10minutes to [3-(3-phenoxyphenyl)propyl]-triphenylphophonium bromide (7.67g; 13.75 mmol) in absolute tetrahydrofuran (40 ml). After stirring for 2hours, α,α,α-trifluoroacetophenone (2.18 g; 12.5 mmol) dissolved inabsolute tetrahydrofuran (10 ml) was added dropwise. After stirring for3 hours at room temperature, the mixture was added to ice-water,extracted with ether and the extract dried over sodium sulphate andevaporated. After chromotography on silica gel using hexane-toluene,there was obtained4-(3-phenoxyphenyl)-1-phenyl-1-trifluoromethyl-1-butene (3.31 g=71.9% oftheory).

EXAMPLE 4 3-Phenoxybenzyl 2-phenyl-2-trifluoromethylethyl ether

Sodium hydride (138 mg; 5.75 mmol) was suspended in dimethoxyethane (20ml). There was then added in turn, with stirring,2-phenyl-2-trifluoromethylethanol (1.0 g; 5.25 mmol), a spatula full ofsodium iodide and 3-phenoxybenzyl bromide (1.39 g; 5.25 mmol). Afterstirring for 4 hours at room temperature, the mixture was added toice-water, extracted with ether, the extract washed with water, driedover sodium sulphate and concentrated. After chromatogrpahy on silicagel using a mixture of hexane and toluene, there was obtained 1.14 g ofproduct (=58.3% of theory).

n²⁰D: 1,546.

Preparation of the Starting Material

A 20% solution of diisobutylaluminium hydride in n-hexane (53.4 ml) wasadded, dropwise, to ethyl α-trifluoromethylphenylacetate (2.9 g; 12.5mmol) (T. S. Everett, S. T. Purrington, C. L. Baumgardner, J. Org. Chem.49, 3702 (1984)) in absolute tetrahydrofuran (50 ml) at about 60° C. Themixture was then allowed to rise to room temperature and stirred for anhour at this temperature. Then at a temperature of 5°-10° C., methanol(10.5 ml) followed by 10% aqueous potassium hydroxide (5.3 ml) wasadded, dropwise. After 1.5 hours, the mixture was filtered and thefiltrate dried over sodium sulphate which was washed with ethyl acetateand the organic phase concentrated. There was obtained2-phenyl-2-trifluoromethylethanol (2.07 g=87.1 of theory).

In a similar way the following compounds were prepared:

Exam- Physical ple constant No. Compound n_(D) ²⁰ 52-(4-Ethoxyphenyl)-2-trifluoromethyl- 1.5451 propyl 3-phenoxybenzylether 6 2-(4-Ethoxyphenyl)-2-trifluoromethyl- 1.5542 propyl3-(N-methylanilino)benzyl ether 7 2-(4-Methoxyphenyl)-2-trifluoromethyl-1.5498 propyl 3-phenoxybenzyl ether 8 2,6-Dichlorobenzyl2-(4-methoxyphenyl)-2- 1.5358 trifluoromethylpropyl ether 94-Fluoro-3-phenoxybenzyl 2-(4-methoxy- 1.5402phenyl-2-trifluoromethylpropyl ether 102-(4-Difluoromethoxyphenyl)-2-trifluoro- 1.5239 methylpropyl3-phenoxybenzyl ether 11 2-(4-Isopropoxyphenyl)-2-trifluoro- 1.5418methylpropyl 3-phenoxybenzyl ether 12 4-Fluoro-3-phenoxybenzyl2-(4-isopropoxy- 1.5331 phenyl)-2-trifluoromethylpropyl ether 132-(4-Isopropoxyphenyl)-2-trifluoromethyl- 1.5390 propyl6-phenoxy-2-pyridylmethyl ether 14 2-(4-Butoxyphenyl)-2-trifluoro-1.5380 methylpropyl 3-phenoxybenzyl ether 152-(4-Butoxyphenyl)-2-trifluoromethylpropyl 1.53054-fluoro-3-phenoxybenzyl ether 162-[4-(2-fluoroethoxy)phenyl]-2-trifluoro- 1.5422 methylpropyl3-phenoxybenzyl ether 17 4-Fluoro-3-phenoxybenzyl 2-[4-(2-fluoro- 1.5350ethoxy)phenyl]-2-trifluoromethylpropyl ether 182-(4-Ethoxyphenyl)-2-trifluoro- 1.5440 methylpropyl6-phenoxy-2-pyridylmethyl ether 192-(4-Difluoromethoxyphenyl)-2-trifluoro- 1.5203 methylpropyl4-fluoro-phenoxybenzyl ether 20 2-(4-Butoxyphenyl)-2-trifluoromethyl-1.5542 propyl 3-(N-methylanilino)benzyl ether 212-(4-Difluoromethoxyphenyl)-2-trifluoro- 1.5256 methylpropyl6-phenoxy-2-pyridylmethyl ether 222-(4-Ethoxyphenyl)-5-(4-fluoro-3-phenoxy- 1.5392phenyl)-2-trifluoromethylpentane 23 5-(4-Fluoro-3-phenoxyphenyl)-2-1.5350 (4-ispropoxyphenyl)-2-trifluoromethylpentane 242-(4-Difluoromethoxyphenyl)-5-(4-fluoro- 1.52233-phenoxyphenyl)-2-trifluoromethylpentane 252-(4-Methoxyphenyl)-5-(3-phenoxyphenyl)- 1.5505 2-trifluoromethylpentane26 5-(3-Phenoxyphenyl)-2-trifluoromethyl-2- 1.5130(4-trifluoromethylsulphonyloxyphenyl)pentane 272-(4-Ethoxyphenyl)-5-(3-phenoxyphenyl)- 1.5454 2-trifluoromethylpentane28 2-(4-Isopropoxyphenyl)-5-(3-phenoxyphenyl)- 1.54102-trifluoromethylpentane 29 2-(4-Difluoromethoxyphenyl)-5-(3-phenoxy-1.5280 phenyl)-2-trifluoromethylpentane 302-[4-(2,2-Dichlorovinyloxy)phenyl]-5- 1.5596(3-phenoxyphenyl)-2-(trifluoromethylpentane 31 4-Fluoro-3-phenoxybenzyl1.5380 2-phenyl]-2-trifluoromethylethyl ether 321-(4-Methoxyphenyl)-4-(3-phenoxyphenyl)- 1.5461 1-trifluoromethylbutane33 1-(4-Ethoxyphenyl)-4-(3-phenoxyphenyl)- 1.54401-trifluoromethylbutane 34 1-(4-Isopropoxyphenyl)-4-(3-phenoxyphenyl)-1.5391 1-trifluoromethylbutane 351-(4-Difluoromethoxyphenyl)-4-(3-phenoxy- 1.5264phenyl)-1-trifluoromethylbutane 364-(3-Phenoxyphenyl)-1-trifluoromethyl-1- 1.5122(4-trifluoromethylsulphonyloxyphenyl)butane 371-(Fluorophenyl)-4-(3-phenoxy- 1.5360 phenyl)-1-trifluoromethylbutane 381-(Methylphenyl)-4-(3-phenoxy- 1.5430 phenyl)-1-trifluoromethylbutane 394-(4-Fluoro-3-phenoxyphenyl)-1-(4-methoxy- 1.5393phenyl)-1-trifluoromethylbutane 40 1-(4-Ethoxyphenyl)-4-(4-fluoro-3-1.5350 phenoxyphenyl)-1-trifluoromethylbutane 414-(4-Fluoro-3-phenoxyphenyl)-1- 1.5303(4-isopropoxyphenyl)-1-trifluoromethylbutane 424-(4-Fluoro-3-phenoxyphenyl)-1- 1.5048trifluoromethyl-1-(4-trifluoromethyl- sulphonyloxyphenyl)butane 431-(4-Difluoromethoxyphenyl)-4-(4-fluoro- 1.51783-phenoxyphenyl)-1-trifluoromethylbutane 444-(4-Fluoro-3-phenoxyphenyl)-1- 1.5356(4-methylphenyl)-1-trifluoromethylbutane 454-(4-Fluoro-3-phenoxyphenyl)-1- 1.5278(4-fluorophenyl)-1-trifluoromethylbutane 464-(4-Fluoro-3-phenoxyphenyl)-1-(3,4-methyl- 1.5460enedioxyphenyl)-1-trifluoromethylbutane 472-(4-Fluoro-3-phenoxyphenyl)-2- 1.5385 (trifluoromethylpropyl)3-phenoxybenzyl ether 48 2-(4-Fluoro-3-phenoxyphenyl)-2-(trifluoro-1.5350 methylpropyl) 4-fluoro-3-phenoxybenzyl ether 492-(4-Ethoxy-3-fluorophenyl)-2- 1.5376 (trifluoromethylpropyl)3-phenoxybenxyl ether 50 2-(4-Ethoxy-3-fluorophenyl)-2-(4-trifluoro-1.5312 methylpropyl) 4-fluoro-3-phenoxybenzyl ether 512-(4-Methoxyphenyl)-2-(trifluoro- 1.5490 methylethyl) 3-phenoxybenzylether 52 4-Fluoro-3-phenoxybenzyl 2-(4-methoxy- 1.5400phenyl)-2-trifluoromethylethyl ether 532-(4-Methoxyphenyl)-2-(trifluoro- 1.5422 methylethyl)6-phenoxy-2-pyridylmethyl ether 54 4-(4-Fluoro-3-phenoxyphenyl)-1-[4-(2-1.5319 fluoroethoxy)phenyl]-1-trifluoromethylbutane 551-[4-(2,2-Difluorocyclopropylmethoxy)phenyl]- 1.52444-(4-fluoro-3-phenoxyphenyl)-1-trifluoro- methylbutane 564-(4-Fluoro-3-phenoxyphenyl)-1- 1.5060[4-(2,2,3,3-tetrafluoropropoxy)phenyl]- 1-trifluoromethylbutane 571[4-(2,2-Dichlorocyclopropylmethoxy)- 1.5450phenyl]-4-(4-(fluoro-3-phenoxyphenyl)-1- trifluoromethylbutane 581-(4-Ethenyloxyphenyl)-4-(4-fluoro-3- 1.5408phenoxyphenyl)-1-trifluoromethylbutane 594-(4-Fluoro-3-phenoxyphenyl)-1- 1.5101[4-(2,2,2-trifluoroethoxy)phenyl]- 1-trifluoromethylbutane 601-[4-(2,2-Difluorocyclopropyloxy)phenyl]- 1.52404-(4-fluoro-3-phenoxyphenyl)-1-trifluoro- methylbutane 611-[4-(2,2,2-Trichloro-1,1-difluoroethoxy)- 1.5236phenyl]-4-(4-fluoro-3-phenoxyphenyl)-1- trifluoromethylbutane 621-(3-Fluoro-4-methoxyphenyl]-4- 1.5420(3-phenoxyphenyl)-1-trifluoromethylbutane 631-(4-tert.-Butylphenyl]-4-(3-phenoxyphenyl)- 1.53661-trifluoromethylbutane 64 2-(4-Ethoxyphenyl)-2-(trifluoro- 1.5444methylethyl) 3-phenoxybenzyl ether 651-(4-Ethoxy-3-fluorophenyl)-4-(3-phenoxy- 1.5376phenyl)-1-trifluoromethylbutane 662-(4-Ethoxyphenyl)-2-(trifluoromethyl- 1.5358 ethyl)4-fluoro-3-phenoxy-benzyl ether 67 4-(4-Fluoro-3-phenoxyphenyl)-1-1.5286 (3-fluorophenyl)-1-trifluoromethylbutane 681-(3-Fluorophenyl)-4-(3-phenoxyphenyl)- 1.5360 1-trifluoromethylbutane69 4-(4-Fluoro-3-phenoxyphenyl)-1- 1.5210(3,4-difluorophenyl]-1-trifluoromethylbutane 701-(3,4-Difluorophenyl)-4-(3-phenoxyphenyl)- 1.52901-trifluoromethylbutane 71 1-(4-tert.-Butylphenyl]-4-(4-fluoro-3- 1.5280phenoxyphenyl)-1-trifluoromethylbutane 721-(3-Fluoro-4-methoxyphenyl)-4-(4-fluoro- 1.53303-phenoxyphenyl)-1-trifluoromethylbutane 731-(4-Ethoxy-3-fluorophenyl)-4-(4-fluoro- 1.52943-phenoxyphenyl)-1-trifluoromethylbutane 741-(4-Difluoromethoxy-3-fluorophenyl]-4- 1.5119(4-fluoro-3-phenoxyphenyl)-1- trifluoromethylbutane 751-(3-Fluoro-4-isopropoxyphenyl)-4-(4-fluoro- 1.52153-phenoxyphenyl)-1-trifluoromethylbutane 764-(3-Phenoxyphenyl)-1-(5,6,7,8-tetrahydro- 1.55342-naphthyl)-1-trifluoromethylbutane 771-(5-Indanyl)-4-(3-phenoxyphenyl)- 1.5541 1-trifluoromethylbutane 781-(4-Phenoxyphenyl)-4-(3-phenoxyphenyl)- 1.5694 1-trifluoromethylbutane79 4-(4-Fluoro-3-phenoxyphenyl)-1-(5-Indanyl)- 1.54611-trifluoromethylbutane 80 4-(4-Fluoro-3-phenoxyphenyl)-1-(5,6,7,8-1.5380 tetrahydro-2-naphthyl)-1-trifluoromethylbutane 811-(4-Fluorophenyl)-4-[3-(4-methoxyphenoxy- 1.5380phenyl)-1-trifluoromethylbutane 82 4-(4-Fluoro-3-phenoxyphenyl)-1-1.5585 (4-phenoxyphenyl)-1-trifluoromethylbutane 831-(4-Fluorophenyl)-(4-pentafluoro- 1.4587phenyl)-1-trifluoromethylbutane 84 4-[3-(4-Chlorophenoxy)phenyl]-1-1.5405 (4-fluorophenyl)-1-trifluoromethylbutane 854-[3-tert.-Butylphenoxy)phenyl]-1- 1.5272(4-fluorophenyl)-1-trifluoromethylbutane 861-(4-Fluorophenyl)-1-trifluoromethyl-4- 1.5037[3-(3-trifluoromethylphenoxy)phenyl]butane 871-(4-Fluorophenyl)-4-[3-(4-methylphenoxy)- 1.5340phenyl)-1-trifluoromethylbutane 88 4-(4-Dimethylaminophenyl)-1- 1.5221(4-fluorophenyl)-1-trifluoromethylbutane 894-[4-(1,1,2,2-tetrafluoroethoxy)phenyl]-1- 1.4580(4-fluorophenyl)-1-trifluoromethylbutane 901-(4-Fluorophenyl)-4-(6-phenoxy)- 1.53162-pyridyl)-1-trifluoromethylbutane 914-(3-Anilinophenyl)-1-(4-fluorophenyl)- 1.5620 1-trifluoromethylbutane92 1-(4-Fluorophenyl)-4-(2,6-difluoro- 1.47802-phenyl)-1-trifluoromethylbutane 93 4-(2-Fluorenyl)-1-(4-fluorophenyl)-1.5648 1-trifluoromethylbutane 94 1-(4-Ethoxyphenyl)-1-trifluoromethyl-1.5144 4-[3-(3-trifluoromethylphenoxyphenyl]butane 951-(4-Ethoxyphenyl)-4-[3-(4-methoxyphenoxy)- 1.5436phenyl]-1-trifluoromethylbutane 96 4-(3-Anilino-4-fluorophenyl)-1-(4-1.5550 fluorophenyl)-1-trifluoromethylbutane 971-(4-Fluorophenyl)-4-(3,4-methylenedioxy- 1.5120phenyl)-1-trifluoromethylbutane 98 1-(4-Ethoxyphenyl)-4-(6-phenoxy-1.5405 2-pyridyl)-1-trifluoromethylbutane 994-[3-(4-tert.-Butylphenoxy)phenyl]-1- 1.5356(4-ethoxyphenyl)-1-trifluoromethylbutane 1004-(3-Phenoxyphenyl)-1-trifluoromethyl- 1.51491-(3-trifluoromethylphenyl)butane 1014-(4-Fluoro-3-phenoxy)phenyl)-1-trifluoro- 1.5078methyl-1-(3-trifluoromethylphenyl)butane 1021-(4-Fluorophenyl)-4-(2,3-methylenedioxy- 1.5094phenyl)-1-trifluoromethylbutane 1034-(4-Ethoxy-2,3,4,5-tetrafluorophenyl- 1.46691-(4-fluorophenyl)-1-trifluoromethylbutane 1041-(4-Allyloxyphenyl)-4-(3-phenoxyphenyl)- 1.5465 1-trifluoromethylbutane105 1-(4-Allyloxyphenyl)-4-(4-fluoro-3-phenoxy- 1.5391phenyl)-1-trifluoromethylbutane 1064-(3-Phenoxyphenyl)-1-(4-propargyloxy- 1.5502phenyl)-1-trifluoromethylbutane 1074-(4-Fluoro-3-phenoxyphenyl)-1-(4-propargyl- 1.5430oxyphenyl)-1-trifluoromethylbutane 1081-[4-(But-2-inyloxy)phenyl]-4-(3-phenoxy- 1.5510phenyl)-1-trifluoromethylbutane 109 1-[4-(But-2-inyloxy)phenyl]-(fluoro- 1.55103-phenoxyphenyl)-1-trifluoromethylbutane 1101-(4-Bromophenyl)-4-(3-phenoxy- phenyl)-1-trifluoromethylbutane 1111-(4-Chlorophenyl)-4-(3-phenoxy- phenyl)-1-trifluoromethylbutane 1121-(4-Bromophenyl)-4-(4-fluoro-3-phenoxy- phenyl)-1-trifluoromethylbutane113 1-(4-Chlorophenyl)-4-(3-phenoxy- phenyl)-1-trifluoromethylbutane 1141,4-Bis-(4-Fluorophenyl)- 1.4860 1-trifluoromethylbutane 1151-(4-Fluorophenyl)-4-(3-methoxy- 1.5040 phenyl)-1-trifluoromethylbutane116 1-(4-Fluorophenyl)-1-trifluoromethyl-4- 1.4660(3-trifluoromethylphenyl)butane 117 4-[3-(3,4-Dichlorophenoxy)phenyl]-1-1.5493 (4-Fluorophenyl)-1-trifluoromethylbutane 1182-(4-Ethoxyphenyl)-2-(trifluoromethyl- ethyl 4-(2-fluoroethoxy)benzylether 119 2-(4-Ethoxyphenyl)-2-(trifluoromethyl- ethyl3-(2-fluoroethooxy)benzyl ether 1202-(4-Chlorophenyl)-2-(trifluoromethyl- ethyl 4-(2-fluoroethooxy)benzylether 121 2-(4-Chlorophenyl)-2-(trifluoromethyl- ethyl3-(2-fluoroethooxy)benzyl ether 1221-(4-Fluorophenyl)-4-[3-(2-fluoroethoxy)-phenyl]-1-trifluoromethylbutane 1231-(4-Fluorophenyl)-4-[4-(2-fluoroethoxy)-phenyl]-1-trifluoromethylbutane 1241-(4-Ethoxyphenyl)-4-[4-(2-fluoroethoxy) phenyl]-1-trifluoromethylbutane125 1-(4-Ethoxyphenyl)-4-[3-(2-fluoroethoxy)-phenyl]-1-trifluoromethylbutane 1261-(4-Chlorophenyl)-4-[3-(2-fluoroethoxy)-phenyl]-1-trifluoromethylbutane 1271-(4-Chlorophenyl)-4-[4-(2-fluoroethoxy)-phenyl]-1-trifluoromethylbutane

The following test Examples illustrate the possible uses of thecompounds of the invention that have been suitably formulated for use.

TEST EXAMPLE 1 Activity against Wingless Stages of Black Bean Aphids(Aphis fabae)

Compounds of the invention were made up as aqueous emulsions at aconcentration of 0.1%. Broad bean (Vicia fabae) plants (one plant perpot) that had previously been infested with wingless stages of the blackbean aphid (Aphis fabae) were sprayed until dripping wet with thesepreparations. After this, the treated test samples were left in thelaboratory under extended daylight conditions for 48 hours. The %mortality of the larvae after 48 hours from the start of the experimentin comparison with untreated controls indicated the level of activity.

In this experiment, the compounds of the preparative Examples 1-43,44-46, 48-51, 53, 64, 66, 67, 69-75, 77, 79, 98 and 101 showed 100%activity.

TEST EXAMPLE 2 Activity against Larvae of the Diamond-Backed Moth(Plutella xylostella).

The compounds of the invention were made up as aqueous emulsions at aconcentration of 0.1%. Cabbage leaves (Brassica olearacea var.botrytis), placed in polystyrene petri dishes, were sprayed with thesepreparations (4 mg spray/cm²). After the sprayed surface had dried, 10young larvae of the diamond-backed moth (Plutella xylostella) wereplaced in each petri dish and thereby exposed to the treated food in theclosed dishes for two days. The % mortality of the larvae after two daysindicated the level of activity.

In this experiment, the compounds of the preparative Examples 2, 3, 4,9, 19, 22, 24, 31-54, 56, 58-60, 62, 72-75, 79-82, 84, 87, 90, 93,95-98, 100 and 101 showed 100% activity.

TEST EXAMPLE 3 Activity against Larvae (L3) of the Mexican Bean Beetle(Epilachna varivestis)

The compounds of the invention were made up as aqueous emulsions at aconcentration of 0.1%. French bean plants (Phaseolus vulgaris) in theprimary leaf stage were dipped in the preparations. For each test, twoplant stems with in total four primary leaves were placed in glass vasesfilled with water and enclosed in plexiglass cylinders. Then five larvaeof the Mexican bean beetle (Epilachna varivestis) at the third larvalstage were put in the glass cylinders and kept for three days underextended daylight conditions. The % mortality of the larvae after threedays indicated the level of activity.

In these experiments the compounds of Examples 2, 4, 5, 9, 11, 22, 24,28, 33 and 62-66 showed 100% mortality.

TEST EXAMPLE 4 Activity against Larvae (L2) of the Cotton Army Worm(Spodoptera littoralis)

Compounds of the invention were made up as aqueous emulsions at aconcentration of 0.1%. Leaflet pairs of beans (Vicia fabae) as well as10 larvae (L2) of the cotton army worm (Spodoptera littoralis) perexperiment were sprayed with 4 mg spray/cm² of these preparations inpolystyrene petri dishes. The closed petri dishes were left in thelaboratory under extended daylight conditions for two days. The %mortality of the larvae after two days indicated the level of activity.

In this experiment, the compounds of the preparative Examples 2, 3, 4,9, 12, 17, 18, 21, 33-46, 49, 50, 52, 54, 58-60, 62, 64-70, 72, 75, 84,90, 96, 98, 100 and 101 showed 100% activity.

TEST EXAMPLE 5 Ovicidal Activity against Eggs of the Cotton Army Worm(Spodoptera littoralis)

The compounds of the invention were made up as aqueous emulsions at aconcentration of 0.1%. One day old eggs that had been laid on filterpaper by fertilised female moths were dipped in the preparations untilthey were completely wet and then placed in closed petri dishes in thelaboratory under extended daylight conditions for four days. The %inhibition of hatching of the eggs in comparison with untreated eggsindicates the level of activity.

In this experiment, the compounds of the preparative Examples 2, 4, 5,64-66, 72, 73, 77, 87, 90 and 96 showed 100% activity.

TEST EXAMPLE 6 Activity against Motile Stages and Eggs of the TwoSpotted Spider Mite (Tetranychus urticae)

Compounds of the invention were made up as an aqueous emulsion at aconcentration of 0.1%. Dwarf bean plants (Phaseolus vulgaris) in theprimary leaf stage, which had been infested with spider mites(Tetranychus urticae), were sprayed with these preparations until theywere dripping wet and left in a laboratory for seven days under extendedaylight conditions. After this, the % mortality of the motile stages onthe one hand and the eggs on the other hand were estimated in comparisonwith untreated controls, using a magnifying glass.

In this experiment, the compounds of the preparative Examples 11, 12,13, 19, 23, 24, 66, 69, 74, 75, 82, 84, 87 and 90-96 showed 100%activity.

TEST EXAMPLE 7 Activity in Prophylactic Treatment of Leaves againstBrown Rice-Hoppers (Niliparvata lugens Stal)

In a heated greenhouse, rice seedlings (about 15 per pot) were grownuntil formation of the third leaf and then sprayed until dripping wetwith an aqueous preparation containing 0.1% of active material. Afterdrying the sprayed leaves, a transparent cylinder was placed over eachpot. 30 Adult brown rice-hoppers (Niliparvata lugens) were introducedinto each pot. After 2 days at 26° C. in the greenhouse, the amount ofdead hoppers was determined. The activity was calculated according toAbbott in comparison with several untreated control pots.

Complete death was reached with the compounds of Examples 4, 12, 19, 22,24, 33, 35-46, 49-55, 59-62, 64-81, 83, 84, 90, 94-96 and 114.

TEST EXAMPLE 8 Tickicidal Activity against Boophilus microplus

9 cm diameter filter papers were impregnated with 1 ml aliquots ofacetone solutions of test compound at various concentrations. The paperswere allowed to dry and then folded into envelopes in which cattle ticklarvae, (Boophilus micoplus) were enclosed and held at 25° C. and 80%R.H. for 48 hours. The percentage mortality of tick larvae was thenrecorded and compared with controls.

The controls gave a mortality of less than 5% whereas compounds ofExamples 2, 3, 5, 9, 10, 11, 12, 13, 22, 25, 26, 28, 32, 33, 37-46, 48,51-55, 57, 58, 60, 62-67, 69-72, 74, 76, 77 and 79-81. caused 50%mortality at a concentration of 300 ppm or less.

TEST EXAMPLE 9 Insecticidal Activity against Lucilia sericata

1 ml aliquots of an acetone solution containing test compound at variousconcentrations were applied to cotton wool dental rolls 1 cm×2 cm,contained in glass vials (2 cm diameter×5 cm long). After drying, thetreated materials were then impregnated with 1 ml of nutrient solution,infested with first instar larvae of sheep blowfly (Lucilia sericata),closed by a cotton wool plug and held at 25° C. for 24 hours.

For the controls the morality was <5% whereas the compounds of Examples2, 5, 7, 9-18, 22, 23, 28, 32-35, 37-46, 51-55, 57, 58, 60-67, 69-72,74, 76, 77 and 79-81 had an LC₅₀ of 100 ppm or less.

TEST EXAMPLE 10 Insecticidal Activity against Musca domestica

Aliquots of acetone solutions of test compounds at variousconcentrations were applied to 9 cm diameter filter papers placed in thebottom of 9 cm diameter petri dishes closed by glass lids. Afterevaporation of solvent, the treated surfaces, together with controltreated with acetone alone, were then infested with adult houseflies,(Musca domestica) and held at 22° C. for 24 hours.

The percentage mortality of the insects was then recorded. Less than 5%mortality resulted in the control treatments whereas the compounds ofExamples 2, 5, 9, 10, 11, 12, 18, 32, 39, 40, 43, 44 and 66 had an LC₅₀of 400 mg/m² or less.

TEST EXAMPLE 11 Insecticidal Activity against Blattella germanica

Aliquots of acetone solutions of test compounds at variousconcentrations were applied to glass plates (10 cm×10 cm). Afterevaporation of solvent, the treated surfaces, together with controlstreated with acetone alone, were then infested with second instar nymphsof the German cockroach, (Blattella germanica), retained on the treatedsurface within PTFE-coated glass rings 6 cm in diameter and held for 24hours at 22° C. The percentage mortality of the insects was thenrecorded.

Less than 5% mortality resulted in the control treatments whereas thecompounds of Examples 2, 3, 5, 7, 9, 11-13, 16, 17, 22, 23, 25, 27, 29,32, 33, 37-46, 51-55, 57, 58, 60-62, 67, 69-72, 74, 76, 77 and 79-81 hadan LD₅₀ of 100 mg/m² or less.

We claim:
 1. An alkane or alkoxyalkane derivative of the formula

in which R₁ is aryl or heteroaryl or these groups substituted by C₁₋₄alkyl, halo-C₁₋₄ alkyl, phenyl-C₁₋₄ alkyl, C₂₋₄ alkenyl, halo-C₂₋₄alkenyl, phenyl-C₂₋₄ alkenyl, C₂₋₄ alkynyl, halo-C₂₋₄ alkynyl,phenyl-C₂₋₄ alkynyl, C₁₋₄ alkoxy, halo-C₁₋₄ alkoxy, phenyl-C₁₋₄ alkoxy,C₂₋₄ alkenyloxy, halo-C₂₋₄ alkenyloxy, phenyl-C₂₋₄ alkenyloxy, C₂₋₄alkynyloxy, halo-C₂₋₄ akynyloxy, phenyl-C₂₋₄ alkynyloxy,alkylsulphonyloxy, haloalkylsulphonyloxy, arylsulphonyloxy, halo, cyano,nitro, aryloxy, haloaryloxy, C₁₋₄ alkylaryloxy, or nitroaryloxy, whereinheteroaryl is benzofuranyl, benzothiophenyl, benzoxazolyl, indanyl orbenzodioxanyl R₂ is hydrogen or C₁₋₄ alkyl, R₃ is hydrogen, cyano orethynyl, R₄ is phenyl or pyridyl or these groups substituted by at leastone of C₁₋₆ alkyl, halo-C₁₋₆ alkyl, phenyl-C₁₋₆ alkyl, C₂₋₆ alkylinterrupted by an O-, N- or S-atom, C₂₋₄ alkenyl, halo-C₂₋₄ alkenyl,phenyl-C₂₋₄ alkenyl, C₁₋₄ alkoxy, halo-C₁₋₄ alkoxy, phenyl-C₁₋₄ alkoxy,C₂₋₄ alkenyloxy, halo-C₂₋₄ alkenyloxy, phenyl-C₂₋₄ alkenyloxy, C₂₋₄alkynyloxy, halo-C₂₋₄ alkynyloxy, phenyl-C₂₋₄ alkynyloxy, aryloxy,haloaryloxy, C₁₋₄ alkylaryloxy, arylamino, haloarylamino, C₁₋₄alkylarylamino, aryl-N-C₁₋₄ alkylamino, aryl-N-C₁₋₄ acylamino, aroyl,haloaroyl, C₁₋₄ alkylaroyl, aryl, haloaryl, C₁₋₄ alkylaryl or halo, andA is CH₂ or O .
 2. Alkane or alkoxyalkane derivative according to claim1, in which R₁ is chlorophenyl, bromophenyl, fluorophenyl, methylphenyl,methoxyphenyl, ethoxyphenyl, difluoromethoxyphenyl, fluoroethoxyphenyl,or trifluoroethoxyphenyl, R₂ is hydrogen or methyl, R₃ is hydrogen, R₄is phenoxyphenyl, fluorophenoxyphenyl or phenoxypyridyl and A is CH₂ orO .
 3. Insecticidal and acaricidal composition which comprises acompound claimed in claim 1 in admixture with an agriculturallyacceptable diluent.
 4. A method of combating insects and acarids whichcomprises applying to the insects or acarids or their locus an effectiveamount of a compound claimed in claim
 1. 5. The method of claim 4 inwhich said compound is[2-(4-ethoxyphenyl)-2-trifluoromethylpropyl](4-fluoro-3-phenoxybenzyl)ether,2-phenoxybenzyl 2-phenyl-2-trifluoromethylethyl ether or4-fluoro-3-phenoxybenzyl 2-(4-methoxyphenyl)-2-trifluoromethylpropylether.
 6. The method of claim 4 in which said compound is5-(4-fluoro-3-phenoxyphenyl)-2-(4-methoxyphenyl)-2-trifluoromethylpentane,4-(3-phenoxyphenyl)-1-phenyl-1-trifluoromethylbutane,1-(4-ethoxyphenyl)-4-(3-phenoxyphenyl)-1-trifluoromethylbutane,1-(3-fluoro-4-methoxyphenyl)-4-(4-fluoro-3-phenoxyphenyl)-1-trifluoromethylbutane,1-(3-fluoro-4-isopropoxyphenyl)-4-(4-fluoro-3-phenoxyphenyl)-1-trifluoromethylbutane,1-(4-ethoxyphenyl)-4-(6-phenoxy-2-pyridyl)-1-trifluoromethylbutane,4-(3-phenoxyphenyl)-1-trifluoromethyl-1-(3-trifluoromethylphenyl)butane,or[4-(4-fluoro-3-phenoxy)phenyl]-1-trifluoromethyl-1-(3-trifluoromethylphenyl)butane.7. A method of combatting insects and acarids which comprises applyingto the insects or acarids or to their locus an effective amount of acompound claimed in claim
 2. 8. Insecticidal and acaricidal compositionaccording to claim 3 in which said compound is[2-(4-ethoxyphenyl)-2-trifluoromethylpropyl](4-fluoro-3-phenoxybenzyl)ether,2-phenoxybenzyl 2-phenyl-2-trifluoromethylethyl ether or4-fluoro-3-phenoxybenzyl 2-(4-methoxyphenyl)-2-trifluoromethylpropylether.
 9. Insecticidal and acaricidal composition according to claim 3in which said compound is5-(4-fluoro-3-phenoxyphenyl)-2-(4-methoxyphenyl)-2-trifluoromethylpentane,4-(3-phenoxyphenyl)-1-phenyl-1-trifluoromethylbutane,1-(4-ethoxyphenyl)-4-(3-phenoxyphenyl)-1-trifluoromethylbutane,1-(3-fluoro-4-methoxyphenyl)-4-(4-fluoro-3-phenoxyphenyl)-1-trifluoromethylbutane,1-(3-fluoro-4-isopropoxyphenyl)-4-(4-fluoro-3-phenoxyphenyl)-1-trifluoromethylbutane,1-(4-ethoxyphenyl)-4-(6-phenoxy-2-pyridyl)-1-trifluoromethylbutane,4-(3-phenoxyphenyl)-1-trifluoromethyl-1-(3-trifluoromethylphenyl)butane,or[4-(4-fluoro-3-phenoxy)phenyl]-1-trifluoromethyl-1-(3-trifluoromethylphenyl)butane.10. Insecticidal and acaricidal composition which comprises a compoundclaimed in claim 2 in admixture with an agriculturally acceptablediluent.
 11. Alkane or alkoxyalkane derivative according to claim 1which is[2-(4-ethoxyphenyl)-2-trifluoromethylpropyl](4-fluoro-3-phenoxybenzyl)ether,2-phenoxybenzyl 2-phenyl-2-trifluoromethylethyl ether or4-fluoro-3-phenoxybenzyl 2-(4-methoxyphenyl)-2-trifluoromethylpropylether.
 12. Alkane or alkoxyalkane derivative according to claim 1 whichis5-(4-fluoro-3-phenoxyphenyl)-2-(4-methoxyphenyl)-2-trifluoromethylpentane,4-(3-phenoxyphenyl)-1-phenyl-1-trifluoromethylbutane,1-(4-ethoxyphenyl)-4-(3-phenoxyphenyl)-1-trifluoromethylbutane,1-(3-fluoro-4-methoxyphenyl)-4-(4-fluoro-3-phenoxyphenyl)-1-trifluoromethylbutane,1-(3-fluoro-4-isopropoxyphenyl)-4-(4-fluoro-3-phenoxyphenyl)-1-trifluoromethylbutane,1-(4-ethoxyphenyl)-4-(6-phenoxy-2-pyridyl)-1-trifluoromethylbutane,4-(3-phenoxyphenyl)-1-trifluoromethyl-1-(3-trifluoromethylphenyl)butane,and[4-(4-fluoro-3-phenoxy)phenyl]-1-trifluoromethyl-1-(3-trifluoromethylphenyl)butane.13. Alkane derivative according to claim 1 which is 1-( 4-ethoxyphenyl)- 4 -( 4 -fluoro- 3 -phenoxyphenyl)- 1-trifluoromethylbutane or 1 -( 4 -ethoxy- 3 -fluorophenyl)- 4 -( 3-phenoxyphenyl)- 1 -trifluoromethylbutane.
 14. Insecticidal andacaricidal composition which comprises a compound claimed in claim 13 inadmixture with an agriculturally acceptable diluent.
 15. A method ofcombating insects and acarids which comprises apply to the insects oracarids or their locus an effective amount of a compound claimed inclaim 13.